1. Field of the Invention
The present invention relates to a device for monitoring a vehicle environment.
2. Description of the Related Art
Motor vehicles are increasingly equipped with devices for monitoring the vehicle environment, which improve the general view and thus can assist in maneuvering or parking, as well. Different types of sensors, e.g., ultrasonic sensors, video cameras, lidar sensors etc. are used for this purpose. Because of functionalities in the automotive field that feature a high degree of automation, such as fully automatic parking, the demands on sensors with regard to accuracy, robustness and reliability become ever greater. The diagnosis or self-diagnosis possibilities of sensors are therefore of increasing importance. Devices for monitoring the vehicle environment with the aid of multiple sensors, such as ultrasonic sensors combined with rear-view cameras, are known from the related art. The related art furthermore includes sensors having additional systems for self-diagnosis. The German patent application publication DE 10 2006 044 786 A1 describes a camera system in a camera-based assistance system of a vehicle, in which a check beam is generated in order to check for soiling of a transparent check body situated on the camera, whereupon a partial beam of the check beam indicative of soiling is detected. The German patent application publication DE 10 2004 028 860 A1 describes an object detection device for vehicles, which is provided in order to detect adhering dirt on a radar. The device includes a dirt-detection circuit for this purpose, which can determine whether dirt adheres to the radar on the basis of time measurements.